8. Equisetum hyemale Linnaeus, Sp. Pl. 2: 1062. 1753.
木贼 mu zei
Plants large. Rhizome creeping or erect, blackish brown, nodes and roots with long yellowish brown trichomes. Aerial stem perennial, monomorphic, green, up to or more than 1 m tall, (3-)5-9 mm in diam. at middle, not branched or base with few erect lateral branches; internodes 5-8 cm. Aerial stem 16-22-ridged; ridges arc-shaped abaxially or nearly rectangular, without conspicuous tubercles or with 2 rows of tubercles; sheath 0.7-1.1 cm, blackish brown or both distal portion and base with a blackish brown band, or only distal portion with a blackish brown band; sheath teeth 16-22, lanceolate, small, 0.3-0.5 cm, teeth of distal portion light brown, membranous, aristate, caducous, teeth of lower portion blackish brown, abaxially 3- or 4-ridged at base, thinly leathery, persistent or falling off early with sheath tube. Strobilus ovate, 1-1.6 cm, 0.4-0.7 cm in diam., apex with small acute tip, sessile. 2n = 216.
Forests, stream banks; 100-3000 m. Chongqing, Gansu, Hebei, Heilongjiang, Henan, Hubei, Jilin, Liaoning, Nei Mongol, Shaanxi, Sichuan, Xinjiang [Japan, Korea, Mongolia, Russia; C and SW Asia, Europe, Central and North America].